If it's anything like the Cougar LS, there should be 4 holes in the factory stereo. There is a U shaped removal tool that you can get (they come in pairs). They will have instruction on how to pull the stereo on them. If you don't want to be bothered to do this yourself, just have the place you got the new radio from install it for you. Should cost an extra $100 or so.
R-12
Take it to Best Buy
In order to take the factory radio out of a 1999 Mercury Cougar you must have DIN tools. Once you make sure you have these, you can insert the tools into the screws on both sides of the stereo. After the tools are inserted, you need to push the tools to the outside of the stereo (slightly) to release the lock mechanism. After the mechanism is released, you can pull the stereo forward and out of the dash. Finally, you need to remove all the connectors and the antenna.
5w30
It will take a skilled mechanic approximately 5 hours to change the fuel pump in your 1991 Mercury Cougar. It can take a novice mechanic much longer.
Take it to theglass repair guy
The 2001 Mercury Cougar does not contain Freon. Freon was banned in 1996. I suggest you take this vehicle to someone who has the knowledge, tools, and skill, to repair the A/C system.
a 95 mercuy cougar takes anywhere from 5 to 7 quarts of transmission fluid
For a Mercury Cougar , 2.5 litre V6 engine : According to the 1999 to 2002 Owner Guides : ( Motorcraft FL-820 engine oil filter )
you need special stereo removal kit commonly know as a clothes hanger
Regular unleaded , 87 octane for the 2.0 and 2.5 engines in a 1999 Mercury Cougar according to the Owner Guide
The fuel pump on a mercury cougar is in the fuel tank. You are going to have to remove the fuel tank, take the lock ring off of the tank, and then pull the pump assembly out.